"I really do believe Kamala Harris is going to win," he said, a few hours before Harris took to the stage. "That doesn't mean I'm not nervous."
The regional organiser from the city of Savannah said people like him would focus on one thing: boosting turnout.
"That means people doing 60-plus-hour weeks and seven days a week of organising. It means volunteers getting out there – phone-banking, calling on voters, canvassing.”
"That's what's going to win this," he said, pointing at the crowd of delegates waving posters for Harris and Walz. "People on the ground."
Nevada Democratic Representative Susie Lee, who represents a district that includes part of Las Vegas – said she was under no illusions the election would be extremely competitive, particularly in her swing state.
"It's not at all in the bag," she said. Some precincts in Nevada, she explained, could be decided by as little as 50 to 100 votes. “Clearly, we have to get people engaged and out to the polls.
"But I'll tell you - I do think people are exhausted with Donald Trump," the congresswoman said. "There's a clear choice between Harris and Trump. I think people see it."
Millions of voters watched the political festival the Democrats put on in Chicago – more than 20m viewers tuned in for each of the first three nights.
The Harris-Walz team will almost certainly get a further bump in the opinion polls after this week. But that’s to be expected following any party convention.
The question will be whether the momentum they have been riding will last, especially as the country learns more about Harris, who has so far avoided tough media interviews and released little in the way of policy detail.
Trump has a grip on nearly half of the country. And they know him well after three successive presidential campaigns.
The Democrats could certainly win this election, but they will have their work cut out.
Additional reporting by Bernd Debusmann Jr